Integrated circuits are typically fabricated within and upon semiconductor substrates, and commonly include deposition of materials upon the substrates. Some material deposited upon such substrates might be subjected to a polishing commonly referred to as chemical mechanical polishing. Such typically involves polishing a substrate with a polishing pad and a slurry provided between the pad and substrate. Both the pad and substrate typically rotate relative to one another, and the slurry includes solid abrasives and chemicals which remove material on the substrate being polished by both chemical and mechanical action.
Capacitors are one type of electronic device of an integrated circuit, for example of logic circuitry and of memory circuitry. In some circuitry, arrays of capacitors are formed. A manner of doing so includes forming openings within a material within which lower electrodes of the capacitors will be formed. Conductive capacitor electrode material, commonly metal, is deposited within the openings and over material within which the openings are formed. The conductive material typically lines yet incompletely fills the openings. Chemical mechanical polishing of the conductive material outwardly of the openings at least to the material under which the metal lies is commonly used to form cup-like/container-shaped capacitor electrodes within the openings. An organic material, such as photoresist, is typically deposited over and within the openings and polished in advance of polishing the capacitor electrode material. Organic material remaining in the openings is subsequently removed by an ashing or chemical etch. Thereafter, one or more capacitor dielectric layers, and outer capacitor electrode layers, are deposited.
It is, of course, desirable that the chemical mechanical polishing to form the isolated container-shaped electrodes occur at a suitably acceptable rate of removal of the photoresist and capacitor electrode layer to maximize the rate of production. The rate of removal is a function of many variables, a significant one of which includes downforce of the polishing pad against the material being polished. Accordingly, it is desirable to maintain sufficiently high downforce to achieve acceptably high rates of polishing. Unfortunately, high downforce can cause some of the material between the capacitor electrode openings to be displaced. This can cause scratching or cracking of the exterior surfaces of the capacitor electrode layers being formed by the chemical mechanical polishing action. Further, the polishing action against photoresist is typically much more mechanical than chemical. Such greater mechanical removing action, particularly in the removal of thick photoresist layers, can cause high mechanical shear forces against the capacitor containers being formed. This can lead to the shearing or breaking of the tops of some of the container-shaped electrodes, which is of course undesirable.
While the invention was motivated in addressing the above identified issues, it is in no way so limited. The invention is only limited by the accompanying claims as literally worded, without interpretative or other limiting reference to the specification, and in accordance with the doctrine of equivalents.